Aglaze is a stock, fond or nage that has been reduced: that is, much ot
the water content is removed by gently simmering. The solid residues, and
all the flavour, stay in the glaze.

Any kind of stock can be used, but it is important to be careful if using
meat stock. Meat stock contains collagen; if the stock is cooked at boiling temperature, there will be a lot of collagen in the glaze. This means the
sauce will become thick more quickly than non-meat glazes. It will then be
impossible to reduce it any more without burning it.

Glazes have a strong flavour and contain a lot of salt, so only use small amounts.